1. Field Of The Invention
This invention relates to a baking machine, more particularly to an automatic baking machine with a preheating capability and a method for controlling the operation thereof.
2. Description Of The Related Art
Presently, a conventional automatic baking machine is controlled to perform a series of baking procedures by a programmable microcomputer control unit which is incorporated therein.
FIG. 1 shows a standard time program of the conventional automatic baking machine (not shown). Initially, dough (not shown) in a container (not shown) of a baking oven (not shown) of the automatic baking machine undergoes a primary kneading procedure at 25.degree. C. for approximately 15 minutes. The dough then undergoes a primary rising procedure at 28.degree. C. for approximately 60 minutes with the activation of a heating device (not shown) of the baking machine. After the primary rising procedure, the dough undergoes a secondary kneading procedure at 25.degree. C. for approximately 18 minutes, the heating device being deactivated at this time. Then, the heating device is again activated to enable the dough to undergo a secondary rising procedure at 32.degree. C. for approximately 20 minutes. A gas release procedure for approximately 0.3 minute is performed after the execution of the secondary rising procedure. Following the gas release procedure, the dough undergoes a final rising procedure at 32.degree. C. for approximately 70 minutes. Then, the heating device remains activated to bake the dough at 200.degree. C. for 40 minutes. Finally, a cooling down procedure is performed for approximately 50 minutes, thus completing the baking operation. Excluding the time for performing the cooling down procedure, the total time for performing the above described procedures is approximately 3 hours and 43 minutes.
Referring now to FIG. 2, a table similar to that illustrated in FIG. 1 is shown. From the table shown in FIG. 2, it can be seen that the time for performing each of the baking procedures is generally less than that for performing each of the baking procedures shown in FIG. 1 when the conventional automatic baking machine is controlled by the conventional programmable microcomputer control unit to perform a shortened time program. Excluding the time for performing the cooling down procedure, the total time for performing the different baking procedures is approximately 2 hours and 20 minutes. This total time is shorter than that of the standard time program.
To ensure the production of high-quality products, it is well known in the art that the dough should be maintained at a rising temperature between 20.degree. C. to 24.degree. C., which is approximately equal to the normal room temperature. However, during winter, the room temperature is usually below 20.degree. C. so that the quality of the products of the conventional automatic baking machine cannot be ensured regardless of whether the automatic baking machine is controlled to perform the standard time program or the shortened time program. To overcome the aforementioned problem, the conventional automatic baking machine is generally equipped with means for providing hot water into the container. When the room temperature is lower than 20.degree. C., the heating device is activated to heat the water stored in the housing (not shown) of the automatic baking machine and the hot water is conveyed automatically into the container to increase the temperature in the container. However, it is too expensive to equip a conventional automatic baking machine with such a hot water providing means.
Referring once more to FIGS. 1 and 2, the times of each of the baking procedures shown in FIG. 2 are generally less than those of the baking procedures shown in FIG. 1, and the rising temperatures for the different rising procedures shown in FIG. 2 are generally higher than those for the rising procedures shown in FIG. 1, thereby resulting in the production of poor-quality products caused by early or insufficient fermentation.